메타데이터
| 항목 |
값 |
| Designation |
C/2021 C4 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-01-17T01:15:25.960320Z |
| Orbit solution date (soln_date, UTC) |
2025-10-28T16:12:33Z |
| Obs used |
234 |
| NEO |
- |
| M1 |
6.900 |
| K1 |
13.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-02-12T14:39:53.769600Z |
| Discovery magnitude (MPC) |
18.73 c |
| Discovery observatory (MPC) |
T05 · ATLAS-HKO, Haleakala |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2021-06-12.0000000 |
| e |
0.99919682 |
| q (au) |
4.504185 |
| a (au) |
5607.929825 |
| i (deg) |
132.842626 |
| Ω (om, deg) |
194.276215 |
| ω (w, deg) |
320.231119 |
| M (ma, deg) |
0.000343 |
밝기
산란 + 전체 선형
$$
M_a = (5.414 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
5.414 |
| n |
6.000 |
| gf |
0.942 |
| gb |
-0.980 |
| k |
1.000 |
| δ90 |
1.000 |
| 파라미터 |
기호 |
범위 |
설명 |
| 태양·지구거리 1 AU에서의 절대등급 |
H0 |
-5 to 20 |
혜성의 고유 밝기 |
| 광도 기울기 파라미터 |
n |
2 to 6 |
태양거리 변화에 따른 밝기 변화율 |
| 전방 산란 비대칭 계수 |
gf |
0.8 to 1 |
전방 산란의 강도 |
| 후방 산란 비대칭 계수 |
gb |
-1 to -0.5 |
후방 산란의 강도 |
| 분할 계수 |
k |
0.8 to 1 |
전·후방 산란 기여도 비율 |
| 먼지/가스 밝기 비 |
δ90 |
1 to 10 |
코마에서 먼지 산란 대비 가스 방출의 상대 기여 |
참고: EPSC-DPS2025-160
천체력
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
09:49:25.71 |
+59:51:20.5 |
HIP 48140 |
15.15 |
| 2026-05-12 12:00 |
09:49:22.20 |
+59:50:10.3 |
HIP 48140 |
16.16 |
| 2026-05-13 00:00 |
09:49:18.83 |
+59:49:00.0 |
HIP 48140 |
17.20 |
| 2026-05-13 12:00 |
09:49:15.59 |
+59:47:49.3 |
HIP 48140 |
18.28 |
| 2026-05-14 00:00 |
09:49:12.50 |
+59:46:38.5 |
HIP 48140 |
19.38 |
| 2026-05-14 12:00 |
09:49:09.54 |
+59:45:27.5 |
HIP 48140 |
20.51 |
| 2026-05-15 00:00 |
09:49:06.72 |
+59:44:16.3 |
HIP 48140 |
21.65 |
| 2026-05-15 12:00 |
09:49:04.05 |
+59:43:04.9 |
HIP 48140 |
22.81 |
| 2026-05-16 00:00 |
09:49:01.51 |
+59:41:53.4 |
HIP 48140 |
23.97 |
| 2026-05-16 12:00 |
09:48:59.10 |
+59:40:41.7 |
HIP 48056 |
24.52 |
| 2026-05-17 00:00 |
09:48:56.84 |
+59:39:29.8 |
HIP 48056 |
23.30 |
| 2026-05-17 12:00 |
09:48:54.71 |
+59:38:17.8 |
HIP 48056 |
22.09 |
| 2026-05-18 00:00 |
09:48:52.71 |
+59:37:05.7 |
HIP 48056 |
20.88 |
| 2026-05-18 12:00 |
09:48:50.86 |
+59:35:53.4 |
HIP 48056 |
19.69 |
| 2026-05-19 00:00 |
09:48:49.13 |
+59:34:41.0 |
HIP 48056 |
18.50 |
| 2026-05-19 12:00 |
09:48:47.54 |
+59:33:28.5 |
HIP 48056 |
17.33 |
| 2026-05-20 00:00 |
09:48:46.09 |
+59:32:15.8 |
HIP 48056 |
16.17 |
| 2026-05-20 12:00 |
09:48:44.76 |
+59:31:03.1 |
HIP 48056 |
15.02 |
| 2026-05-21 00:00 |
09:48:43.57 |
+59:29:50.3 |
HIP 48056 |
13.90 |
| 2026-05-21 12:00 |
09:48:42.51 |
+59:28:37.3 |
HIP 48056 |
12.80 |
| 2026-05-22 00:00 |
09:48:41.58 |
+59:27:24.3 |
HIP 48056 |
11.74 |
| 2026-05-22 12:00 |
09:48:40.79 |
+59:26:11.3 |
HIP 48056 |
10.72 |
| 2026-05-23 00:00 |
09:48:40.12 |
+59:24:58.1 |
HIP 48056 |
9.75 |
| 2026-05-23 12:00 |
09:48:39.58 |
+59:23:44.9 |
HIP 48056 |
8.86 |
| 2026-05-24 00:00 |
09:48:39.16 |
+59:22:31.6 |
HIP 48056 |
8.08 |
| 2026-05-24 12:00 |
09:48:38.88 |
+59:21:18.3 |
HIP 48056 |
7.42 |
| 2026-05-25 00:00 |
09:48:38.72 |
+59:20:05.0 |
HIP 48056 |
6.94 |
| 2026-05-25 12:00 |
09:48:38.69 |
+59:18:51.6 |
HIP 48056 |
6.66 |
| 2026-05-26 00:00 |
09:48:38.78 |
+59:17:38.2 |
HIP 48056 |
6.62 |
| 2026-05-26 12:00 |
09:48:39.00 |
+59:16:24.7 |
HIP 48056 |
6.82 |
| 2026-05-27 00:00 |
09:48:39.34 |
+59:15:11.3 |
HIP 48056 |
7.24 |
| 2026-05-27 12:00 |
09:48:39.80 |
+59:13:57.8 |
HIP 48056 |
7.84 |
| 2026-05-28 00:00 |
09:48:40.39 |
+59:12:44.3 |
HIP 48056 |
8.59 |
| 2026-05-28 12:00 |
09:48:41.10 |
+59:11:30.8 |
HIP 48056 |
9.45 |
| 2026-05-29 00:00 |
09:48:41.93 |
+59:10:17.3 |
HIP 48056 |
10.40 |
| 2026-05-29 12:00 |
09:48:42.88 |
+59:09:03.9 |
HIP 48056 |
11.41 |
| 2026-05-30 00:00 |
09:48:43.95 |
+59:07:50.4 |
HIP 48056 |
12.47 |
| 2026-05-30 12:00 |
09:48:45.14 |
+59:06:37.0 |
HIP 48056 |
13.56 |
| 2026-05-31 00:00 |
09:48:46.45 |
+59:05:23.6 |
HIP 48056 |
14.69 |
| 2026-05-31 12:00 |
09:48:47.88 |
+59:04:10.2 |
HIP 48056 |
15.84 |
| 2026-06-01 00:00 |
09:48:49.42 |
+59:02:56.9 |
HIP 48319 |
16.76 |
| 2026-06-01 12:00 |
09:48:51.08 |
+59:01:43.6 |
HIP 48319 |
16.56 |
| 2026-06-02 00:00 |
09:48:52.86 |
+59:00:30.3 |
HIP 48319 |
16.42 |